Magnetic Field of a Solenoid and a Toroid

A toroid of narrow radius of $10 \mathrm{cm}$ has 1000 turns of wire. For a magnetic field of $5\times {10}^{-2}\mathrm{T}$ along its axis, how much current is required to be passed through the wire? 

A solenoid of length $\mathrm{\pi m}$ and $5 \mathrm{cm}$ in diameter has winding of 1000 turns and carries a current of $5 \mathrm{A}$. Calculate the magnetic field at its centre along the axis.